Photo electric system



Jan. 5," 1932.

E. H. GRElBAcH I PHOTO ELECTRIC SYSTEM 3 Sheets-Sheet Filed Dec. 4;, 1929 Janl"5, 1932. E. H. GREIBACH PHOTO ELECTRIC SYSTEM Filed Dec. 4, 1929 3 Sheets-Sheet 2 Jan. 5, 1932. E. H. GREIBACH PHOTO ELECTRIC SYSTEM Filed Dec. '4, 1929 s sheets-sheet s qn "3 N v Q 3 Q Q 1 I a p v 1% a f 1 $1 lg R Q IIIII'IH NVENTOR W BY g; Q M

Q; A ORNEY P Patented Jan. 5, 1932 UNITED STATES PATENT OFFICE EMIL H.

GREIBACH, OFNEW YORK, N. 1%., Assreivon. 'ro PAGEN'I ELECTRIC eomrm,

y me, or NEW YORK, N. Y., A CORPORATION or NEW YORK PHOTO ELECTRIC SYSTEM Application filed. December 4, 1929. Serial No. 411,499.

This invention relates to photoelectric systems generally, but more particularly to apparatus of. this sort as associated with sound film recording and projecting apparatus.

Special objects of the invention are to improve apparatus-of this type in the matters of greater simplicity and ruggedness of mechanical construction; to make the apparatus in a form readily applicable to existing mov- 1o ing picture machines; to facilitate focusing and setting of the parts; to enable quick replacement of the excitor lamps and to increase the efliciency of the optical system.

Other objects and the novel features of construction, combinations and relations of parts by which the objects are attained will appear in the course of the following specification.

The drawings accompanying and forming part of this specification illustrate one of the practical commercial embodiments of the invention, but the invention is not limited to the details of construction illustrated, as will be clear from-the broad scope of the patent claims.

Figure 1 is a vertical sectional view of a form of the apparatus as it is applied to a standard motion picture projecting machine. Figure 2 is a broken plan view of such periscope.

Figure 3 is a broken part sectional and diagrammatic view of the optical system.

Figure 4 is a detail view of the detachable periscope. t 5 Figure 5 is a broken enlarged View of the optical slit and mask construction. Figures 6 and 7 are sectional views of the same as taken on substantially the planes of lines 6 and 77 of Figure 5.

Figure 8 is a broken part sectional'detail of the adjustable film guide roller.

Figure 9 is a sectional view of one of the interchangeable lamp holders with an excitor mounted therein.

Figure 10 is a plan View of the holder.

Figure 11 is a broken .detail of the yielding film gate structure.

In Figures 1 and 2 the entire mechanism is shown as mounted in or supported by a casing 12, which may be attached by the bolts 13 to the base'of a projecting machine in position to directly receive the film 14' from the projector through an opening 15 in the top of the casing.

The film from the projector passes first over an idler guide roll 16, and thence through a film gate made up of the arcuate shoe 17, and spring strips 18. This gate shoe has an exposure opening 19 in it, as shown in Figure 3. The film is advanced down through thegate by suitably chronously by sprocket bottom of the casing through driven from the projector or syntherewith and is thenadvanced 21 over guide roll 22 and out the a roller passage CO0 cratin ed e retainin a constantly running sprocket 20,

23. A guide is shown at24 to. strip the film from the teeth of sprocket 21 and insure its free passageon out of the machine. The excitor lamp. 25 is shown located in a separate compartment at the back of the casing with its filament in line with the optical tube 26 and the photoelectric cell'27 is shown mounted in a'separate' compartment at the front of-the casing in line with the optical tube. These two compartments are preferably 28. 29, enabling quick access to the lights.

Itis important that there be no interruption through failure of the light source, and. consequently, a special feature of the invention resides in the provision and mounting of extra light-bulbs so that they may be quickly shifted one after theother into the optical axis. This is accomplished in the'illustration by mounting the lamp bulbs in holders or bases 30 arranged to slide in a trackway 31 extending transversely of the optical axis.

mounted in insulation 35 and slidingly projectcd by enclosed springs 36, Figure 9, which connect at the top with center contacts 37, slidingly projecting through insulating discs 38 to engage the center lamp contacts 39. The lamp bases 40 are shown as having projecting provided with readily removable covers tabs 41 on opposite sides of the same, designed to enter through notches 42, Figure 10, in the overstanding confining flange 43. \Vhen so entered. the lamp bulbs are given a half turn to the position shown in Figure 9, where the mounting tabs or lugs 41 are fully engaged beneath the overstanding flange 43 and in such position, the lamps are held with the axis 44 of the filament in transverse alinement with the optical axis, as indicated in Figure 1. This method of mounting allows a certain leeway for turning the lamp to bring the filament in proper position, and the lugs are preferably made of relatively thin metal, as indicated, so that they will bend to enable the lamp being twisted one way or the other in its socket, space being provided at 45 (Figure 9) in the socket to allow a certain latitude of such twisting movement of the lamp base in the socket.

Located in the lamp trackway at a point to engage the bottom contact 34 of the socket when the lamp filament is alined with the optical axis, is an insulated current conducting contact'spring 46, having a depression 47 as shown in Figure 1, to catch and hold the bottom contact when the socket is thus properly centered.

As shown in Figure 2, the lamp track extends sufiiciently' to one or both sides of the optical axis to enable one or more extra lamp carrying sockets to be mounted alongside the active lamp, ready to be pushed over into the active contact making position the instant the lamp in use should fail. As a further precaution, extra lamp bulbs 25 may be mounted in spring brackets 48 on the back or and removably held by the bolts 49 in the split clamps 50, Figurcs 1 and 2. As shown in Figure 3, the optical system consists of the lenses 51, 52, arranged to condense the light from the excitor onto the opening 53 in the slit holder 54, so that the light passes in a narrowed beam from the slit 55 to the objective lens 56 in the forward end of the tube through the film slit 19 to the front lens 57, which condenses the projected light in the photoelectric cell.

The slit holder 54 is shown in the form of a sleevesetin the back end of the tube 26 against a shoulder 58 and alined by means of a pin 59 entering in a slot 60 in the side of the sleeve. The slit 55 is shown provided by cooperating slit plates 61, fastened on the sleeve over the large light opening 53 and formed length of the light slit, as shown particularly in Figure 7.

The objective lens 56, Figure 3, is shown as carried. by a lens holder 66, mounted in a ring 67 which screws into the end of the lens tube and in the illustration this ring is definitely located with respect to the end of the tube by means of a spacer ring 68 interposed between the mounting ring and the end of the tube. Spacer rings of different thicknesses may be employed to predetermine different positions of the objective lens and these spacer rings may be omitted to enable the mounting ring to come up against the end of the tube for another definite setting of the objective lens. The objective lens tube 66 is shown as entering a socket 69 in the back of the film guiding block 17, so as to confine and concentrate the light on the film passing over the guide.

The condensing lens 52, Figure 3, is shown as definitely positioned by beating against the end of the slit ring 54 and the lens 51 is definitely positioned by bearing against a retaining ring 70 screwed on the end of the tube, the spring 71 placed between the lenses holding them against the positioning seats described.

The front condensing lens 57 is shown as definitely positioned by being forced by a spring 72, Figure 3, against an internal shoulder 73 in the sleeve 74, which is accurately positioned in the front wall of the casing, Figure 1, by having an external flange 75 hearing against the inner face of the wall and held so by a ring 76, screwed on the outer end of the sleeve and bearing against the outer face of the wall. This securing ring also serves as a retainer for the spring 72, t

the same bein indicated as having an internal flange 7 serving as an abutment for the outer end of the spring.

For focusing purposes, a periscope may be employed and a special feature of the same is that this periscope is readily removable from the optical system. For the purpose the lens tube is provided with an opening 78 in the outer side of the same; Figure 2. into which the inner end of the periscope tube '79 fits, the latter having a pin 80 on the inner end. of the same to enter a notch 81 in the edge of the periscope opening to interlock the periscope in proper position with the prism 82 properly disposed in the optical axis. This prism is shown as mounted in an open setting 83 supported at the inner end of the periscope tube. When the periscope is removed, the opening in the side of the lens tube may be closed by turning the cover sleeve 84 over the same, said sleeve being shown in Figure 2 as having an opening 85 to uncover the periscope opening when alined therewith.

The film gate strips 18 are shown, in Figures 1 and 11 as carried by a lever 86 pivoted at 87 and tensioned by a spring 88 toward the stationary film guiding support 17. A cam or eccentric 89 is shown mounted on this lever in position to engage a shoulder 90 on the frame or. casing and this eccentric is shown as adapted to be turned by a'handle 91 r so as to force the gate lever back from the stationary film support, as in Figure 11, or to means are all mounted on a single bracket 95,

detachably fastened in place on the inner side wall of the casing by screws 96, so that in case of need, these associated parts may be taken put as a unit without disturbing their associatedrelations.

.If desired, all-electrical connections to the apparatus may be'made by a single multipronged plug, such as shown at 97 in Figure 1, designed to fit a corresponding socket or terminal block suitably mounted on the apparatus.

The film advancing portion of the apparattisinay-be suitably driven from the moving picture machine. or be independently driven, as desired. The optical tube may be readily adjusted in the supporting clamp structure provided. therefor or be entirely removed therefrom. The main compartment of the machine shown in Figure 2 as having a lunged door 98 to provide ready access to the optical system and associated parts. As

appears particularly in Figure 3, the light is flooded in a relatively wide beam through the aperture 53 onto'the slit 55. so that no diflicult focusing is involved, and so that the light issuing through the slit is uniform in its cross sectional outline. The masks are readily interchangeable to "ary the length of the slot. The periscope similarly is readily removable. is out of the way when not required and at the same time can be quickly applied when needed.

If the lamp burns out, there need be practically no interruption in the operation as it is only necessary to push the spare lamp over in place of the burned out lamp. this I being a simple. positive operation by means of the coaction between the bottom contact on the lamp socket with the current conducting contact spring which holds the socket in position with the lamp filament lined up with the optical axis. The defective lamp man be re flaced by one of the extra lamps and a spare be thus provided, ready to be shifted back into alinement with the optical axis if the second'lamp should fail for any reason. v

The film guiding spool 16 is illustrated as made up of two end spool sections 99, 100, Figures 2 and 8, with a. spring 101 on the shaft of the spool, and forcing the two end heads together against an abutment shoulder 102. This construction enables the heads of the spool to yieldingly grip the edges of the film, confining and directing it accurately to the film gate. The abutment 102 is indicated as a stop collar adjustably secured on the shaft by a screw 103 to form a fixed abutment for definitely positioning the sound record edge of the film with respect to the optical system. By this means the sound track can be brought into absolute register with the optical axis and in any adjusted position, the film will be properly gripped at the edges by means of the spring take-up 011 the spool head. i

The periscope can only be mounted on the lens tube and used when the door of the casing is open, as will be clear. from Figure 2,

and this relation constitutes a safety measure,

insuring the removal of the periscope before the machine is operated.

\Vhat is claimed is:

1. In apparatus of the character disclosed, the combination of an optical system, an excitor lamp at one end of the same and a photoelectric cell at the opposite end, a socket for said excitor lamp and a trackway for mounting said socket in transversely movable relation at the end of the optical system, enabling the replacement of one lamp for another by the transverse shifting of a lamp carrying socket in the trackway aforesaid.

2. In apparatus of the character disclosed,

'the combination of an optical system, an

excitor lamp at one end of the same and a photoelectric cell at the opposite end, a socket for said excitor lamp, a trackway for mounting said socket in transversely movable relation at the end of the optical-system, enabling thereplacement of one lamp for another by the transverse shifting of a lamp carrying socket in the trackway aforesaid, a current conducting lamp-engaging contact. on the socket and current conducting contacts on the socket and trackway cooperating in the position of alinement of the lamp with the optical axis.

3. In apparatus of the character disclosed, the combination of an optical system, an excitor lamp at one end of the same and a photoelectric cell at the opposite end, a socket for said excitor lamp and a trackway for mounting said socket in transversely movable relation at the end of the optical system, enabling the replacement of one lamp for another by the transverse shifting of a lamp carrying socket in the trackway aforesaid, said trackway being of suflicient transverse extent to support a number of lamp sockets alined in readiness, one to be shifted in place of. the other.

i. In apparatus of the character disclosed, a lens tube having an opening in one side of the same, a p'eriscope detachably engageable in said opening and a cover for said tube opening for closin the same when the periscope is removed.

In apparatus of the character disclosed, a lens tube having an opening in one side of the sa mc. a detachable periscope, means for removably supporting said periscope in definitely related position over said opening in the lens tube and means for covering the opening in the tube when said periscope is removed.

'6. In apparatus of the character disclosed, the combination of a lens tube, a lens holder removably and adjnstably engaged with one end of the tube and an annular spacing member carried by said lens holder. for definitely positioning the same relative to the end of the lens tube.

7. In apparatus. of the character disclosed, a slit holder having a. wide slot, slit members carried by said holder and cooperating to form a narrow slot in line with the wide slot of the holder, said slit members having cooperating parts providing aguideway for a slit-length determining mask. I 8. In ap aratus of the character disclosed, a slit hold zr having a wide slot, slit members carried by said holder and cooperating to form a narrow slot in line with the wide slot of the holder, said slit members having cooperating'parts providing a guidcway for a slit-length determining mask, a lens tube in which the slit holder is mounted, said lens tube having a slot in one side of the same in line with the guideway of the slit members and a mask plate insertable through the slot into said guideway.

9. In apparatus of the character disclosed, the combination with an optical system of an cxcitor lamp having bendable supporting tabs at opposite sides of. the base of the same and a socket freely receixing the base of the lamp, said socket having means for holding said bendable tabs and the base of the lamp being shiftable in the socket when the tabs are bent to hold the lamp in different positions and means for supporting the socket with the lamp adjusted therein in alignment with the axis of the optical system.

10. In combination with a lens tube, an cxcitor lamp having bendable tabs projecting from opposite. sides of the base of the lamp,

a socket for holding said tabs in a definite I position, said lamp being shiftable with respect to the socket in the bending action of the tabs 'when the latter are held in the socket,'means for supporting the socket with the lamp carried thereby aligned with the optical axis of the lens tube.

the tabs when the latter are held in thesocket and spring pressed contact means carried by the socket and operative in all adjusted positions of the lamp in the socket, means for supporting the socket with the lamp carried thereby aligned with the optical axis of the lens tube.

12. In apparatus of the character disclosed, a lens tube, an excitor lamp socket having grooves in opposite sides of the same, a spring terminal contact in the bottom of the socket, a t-rackway for the socket having flanges engaged in the grooves in the socket and a contact terminal between the track flanges co-- operating with the spring contact of the socket for yieldingly retaining the socket in definite position in the trackway in line with the lens tube.

13. In'apparatus of the character disclosed,

the combination of a casing having a door" providing access to the interior of the same, an optical system including a lens tube. w1thm the casing and a periscope removably attachable to the lens tube when said door is.

open, saiddoor being closable only when the lens tube. v y

14. In apparatus of the character disclosed, the combination of a lens tube, a lamp holder, an excitor lamp universally adjustable in said holder and having means cooperating with the holder for releasably retaining said lamp in its universally adjusted relation in the holder and means for supporting and retaining said holder inpredetermined definite relation to the lens tube.

15. In apparatus of the character disclosed, the combination of an excitor lamp, a holder for said lamp, said lamp having a universally adjustable mounting in said holder and cooperating means on the lamp and holder for releasably retaining the lamp in universally adjusted relation in the holder and a support having means for positioning and ret aining the holder in predetermined relation.

In testimony whereof I affix my signature.

EMIL H. GREIBACH. 

